Internal combustion engines are used in a wide variety of applications including, for example, automobiles, boats, aircraft, lawnmowers, tractors, snow blowers, and power machinery. Many such internal combustion engines employ a carburetor to provide an appropriate fuel/air mixture (often referred to as “charge”) to the combustion chamber(s) of a cylinder block. Further, in many such engines that employ two or more cylinders, an intake manifold is employed that links the carburetor to the multiple cylinders. In some such engines, the carburetors have two or more barrels by which charge is generated for different respective engine cylinders that are coupled to the respective barrels by way of dedicated channels within the intake manifolds linking the cylinders with the carburetors.
In many applications involving internal combustion engines, high output power levels from the engines are desirable. Yet the maximum amount of power that can be output by a given internal combustion engine having a carburetor is limited by the size or displacement of the engine, as well as the size of the carburetor venturi and the rated RPM. In the case of multi-cylinder internal combustion engines in which the cylinders are respectively coupled to respective barrels of multi-barrel carburetors, one known manner of enhancing the output power of such an engine is by providing a communication channel or bridge that links multiple barrels of the carburetor and/or corresponding intake tubes within the intake manifold. Such a communication channel can allow charge to flow between the different barrels/intake tubes/cylinders of the engine, and as a result can allow (at least some of the time) a given engine cylinder to receive charge from both barrels, thus increasing power from that cylinder.
Although such communication channels can allow multi-cylinder engines to achieve higher power levels, such conventional channels do not always produce consistent or desirable output power results. Further, conventional communication channels, while tending to enhance engine output power, also tend to alter the fuel/air mixture provided to the engine cylinders and increase engine emissions. This is undesirable, since reduced emission levels from internal combustion engines are increasingly desired. Indeed, several regulations have recently been enacted, and/or potentially will be enacted in the near future, requiring engines to meet more stringent emissions standards.
For at least these reasons, therefore, it would be advantageous if an improved mechanism for achieving higher output power levels from a multi-cylinder internal combustion engine with a multi-barrel carburetor could be developed. In at least some embodiments, it would be desirable if such an improved mechanism not only enhanced output power levels of the engine but also did so in a manner that did not greatly increase engine emissions.